Wide linear range orthogonal micro-fluxgate with multi-segmented core

A method to increase the linear operating range and improve the sensitivity of orthogonal micro-fluxgates through multi-segmented core was introduced in this study. The multi-segmented core consisted of several rows, and each row consisted of many segments. The simulated results showed that segmented cores had the same effect on increasing demagnetisation of axial direction compared with shortened cores. Moreover, metameric cores produced longer core length and more turns of detection coils, which was beneficial for sensitivity. Longer excitation wire corresponding to the multi-segmented core produced higher input impedance, which reduced the useless power consumption in driving circuit. The test results showed that: the linear operating range increased as the number of segments; the sensitivity increased as the number of the rows; the spectrum characteristic did not disturb by increasing the number of the rows or segments; the magnetic noise increases with increasing the number of segments and decreases with increasing the number of rows; and finally the additive range of ±800 μT, sensitivity of 43.4 V/T and magnetic noise of 28.4 nT/rtHz at 1 Hz were achieved with ten rows five segments core structure in an orthogonal micro-fluxgate.